Advances in technology have resulted in smaller and more powerful computing devices. For example, there currently exist a variety of portable personal computing devices, including wireless computing devices, such as portable wireless telephones, personal digital assistants (PDAs), and paging devices that are small, lightweight, and easily carried by users. More specifically, portable wireless telephones, such as cellular telephones and Internet Protocol (IP) telephones, can communicate voice and data packets over wireless networks. Further, many such wireless telephones include other types of devices that are incorporated therein. For example, wireless telephones can also include a digital still camera, a digital video camera, a digital recorder, and an audio file player. Also, such wireless telephones can process executable instructions, including software applications, such as a web browser application, that can be used to access the Internet. As such, these wireless telephones can include significant computing capabilities.
Digital signal processors (DSPs), image processors, and other processing devices are frequently used in portable personal computing devices that include digital cameras, or that display image or video data captured by a digital camera. Such processing devices can be utilized to provide video and audio functions, to process received data such as image data, or to perform other functions.
One type of image processing involves correcting and improving overall optical performance of camera modules. Camera modules including a lens system and an image sensor are commonly supplied to wireless telephone manufacturers as a complete unit. Camera modules may optionally include a focus device or mechanism, an autoexposure device, or any combination thereof. These elements make up the front end of a camera and are referred to as a camera module. Camera modules are generally tested to ascertain their overall optical performance. Typically, an image of a reflective test target is taken using the camera module. The target has various patterns thereon to measure lens sharpness. To measure additional parameters, such as vignetting and lens tilt, additional test targets and images would need to be captured and analyzed. In addition, the camera module and the various test targets need to be carefully aligned. Such an ad-hoc testing procedure is tedious, time consuming, and prone to error.